Apparatus for cooling air

ABSTRACT

An apparatus for providing a stream of substantially dry, evaporatively cooled air for use in dwellings and the like, characterized by the utilization of a high-speed blower for establishing a stream of air, a continuously rotating watersaturated pad interposed in the stream adapted to provide a radial discharge of moisture-ladened, evaporatively cooled air and a substantially dry perforated pad interposed in the stream of air between the blower and the periphery of the saturated pad for extracting moisture from the air, whereby a stream of relatively dry cooled air is provided.

Unitedv States Patent 11's] 3, 3,705,479

McPherson [451 Dec. 12, 1972 [541 APPARATUS FOR COOLING AIR 2,342,8412/1944' Carraway, ..261/92 x 72 I nt w M I Carraway X 1 fith, 'l g E2,809,817 10/1957 Munters; ..26l/83 x 3,306,591 2/1967 Valazza ..261/92x 221 Filed: May 15,1969 3,365,862 1/1968 Flury ..55/230 21 A 1. N l 1pp 824778 Primary Examiner-Dennis E. Talbert, Jr.

Attorney-Huebner & Worrel [52] US. Cl. ..55/223, 55/224, 55/226,

55/227, 55/232, 55/234, 55/259, 55/267, [57] ABSTRACT 55/410 55/41855/467 7 An apparatus for providing a stream of substantially dry,evaporatively cooled air for use in dwellings and lil $533588 1357583226 32"? tht hhtt thttttttthtth tht ttthhtthh t htth- 55,410 418 467 490261/83 f speed blower for establlshing a stream of an, a cori- 62/531 fjtmuously rotating water-saturated pad interposed 1n the stream adaptedto provide a radial discharge of I 'v t moisture-ladened, evaporativelycooled air and a sub- [56] 'Rgferences Cited stantially dry perforatedpad interposed in the stream UNITED STATES PATENTS of air bgtwegnfth'eblower, and the periphery hof the saturate pa or extracting moisture romt e air,

whereby a stream of relatively d y cooled air is Pro- 9 9 6 leg on t d d2,177,869 10/1939 Crawford ..261/92 X at 2,300,580 11/1942 Loprich..26l/30 t 1 Claim, 3 Drawing Figures PKTE'NTEDnEcm 1972 3,705,479

WILSON W MC PHERSON INVENTOP A T TOR/1 E VS 1 APPARATUS FOR COOLING AIRBACKGROUND OF THE INVENTION stantially dry, evaporatively cooled air forpurposes of reducing temperatures in dwellings, warehouses and the like.

The prior art includes numerous devices and systems for evaporativelycooling and delivering atmospheric air for purposes of coolingbuildings. Normally, these devices force a stream of air through awater-saturated pad, whereby evaporation of water and a resultingcooling of the air is achieved as water within the pad is evaporated inthe presence of the stream of air. One of the undesirablecharacteristics of such air is that air delivered through a wet padusually becomes heavily ladened with moisture particles, aswell as watervapor. Since the conversion of water to water vapor cools by evaporationwhile the particlization of water does not, burdening the air with waterparticles is undesirable. Among the disadvantages incidentto thepresence of moisture particles is the inability of cooling'devices ofthe evaporative type to function efficiently under such conditions.Evaporation is inhibited by the presence of excessive moisture andmoisture-ladened air does not permit adequate evaporation from the bodyfor personal comfort. Furthermore, delivery of excessively moist air forcooling purposes can be harmful to the environment and even result inindoor precipitation.

SUMMARY OF THE INVENTION This invention overcomes the aforementioneddifficulties through the use of a novel arrangement of water absorbent,perforated pads employed in a manner such that a first pad is saturatedwith water and a stream of air is forced therethrough for achieving anevaporative cooling of the air, and a second pad is positioned in thestream and employed for extracting from the evaporatively cooled air,water particles suspended therein prior to the delivery of the thuscooled air.

Accordingly, an object of the instant invention is to provide animproved apparatus for evaporatively cooling ambient atmospheric air.

Another object is to provide an improved evaporative cooler for use inproviding relatively dry, evaporatively cooled air.

Another object is to provide an efiicient evaporative cooler whichemploys a drum-mounted, continuously rotating pad partially submerged ina water bath for delivering relatively dry, evaporatively cooledatmospheric air for use in a relatively humid atmospheric environment.

Another object is to provide in an evaporative cooler variable speeddrive means adapted to dictate the rates of rotation imposed on adrum-mounted .cooler pad, whereby the water content of air deliveredthrough the pad effectively may be controlled.

Other objects and advantages of the present invention will subsequentlybecome more clearly apparent upon reference to the following descriptionand accompanying drawing.

office buildings,

2 BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a sectioned side view of anevaporative cooler embodying the principles of the present invention.

FIG. 2 is a sectioned end view taken generally along line 22 of FIG. 1.

FIG. 3 is a sectioned end view taken generally along line 3-3 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning first to FIG. 1, thereinis illustrated an evaporative cooler embodying the principles of thepresent invention mounted in a substantially closed housing 10. Thehousing includes suitable mounting brackets 11, a system intake duct 12,including a pair of coaxially arranged openings 13, FIG. 2, and a singlesystem discharge duct 14, through which air is drawn into the cooler anddischarged as a stream of substantially dry, evaporatively cooled air.By substantially dry is meant that it contains a minimum of waterparticles although, of course, it does contain water vapor.

Within the housing 10, adjacent to the intake duct 12, there is provideda water bath, generally designated 16. The water bath includes awater-tight pan 18 which receives and retains therein a replenishablesupply of water. Within the pan there is displaceably disposed anarcuate segment of a cylindrical, pervious, evaporative cooler pad 20.The pad is open-ended, at both ends, and is arranged in coaxialalignment with the openings 13 of the intake duct 12 so that air drawninto the duct passes through the openings at ends of the pad and isradially discharged through the pad. The pad is formed of any convenientwater absorbent material, such as excelsior, for example, and issupportedfor rotation by means including a cylindrical drum 22 whichreceives and supports the pad in a circumscribing relationship about itsperipheral surface. The drum is rotated about its longitudinal axis andserves to displace the pad through the pan 18 for causing the materialthereof to become water saturated as it passes through the water bathand to become evaporatively dried as air is radially dischargedtherethrough and for thus achieving desired evaporative cooling.

The drum 22 includes a pair of spaced end supports 24, each of which isof a generally disk-shaped configuration and includes a plurality ofspoke-like members 26 extending radially from hubs 28. The supports 24are disposed in parallel planes with the hubs being fixedly secured toan axle shaft 30 extended through the drum 22 along its axis ofrotation. It is intended that the axle shaft 30 serve to support thedrum and impart selected rates of rotation thereto. Therefore, the hubs28 are secured to the shaft by any convenient means, such as setscrews32, for preventing rotation of the axle shaft relative to the hubs sothat a driving connection is established therebetween.

The spaced supports 24 are interconnected by any convenient means.However, as presently employed, the distal ends of the spokes 26 aresecured to a plurality of connecting stringers 34 which extend to couplethe members 24 into a unitary drum-like structure having an axleextended therethrough. It should readily be apparent that the members 24can be joined through various types of connecting members, such asperforated screens or cylinders having perforated walls, for example.Furthermore, if desired, the pad itself may be of a relatively rigidconstruction so that the pad is supported without requiring the use ofadditional support means. In any event, it is to be understood that thecylindrical pad 20 is supported for rotation by the drum 22 which is, inturn, supported for rotation by the axle 30 so that successive segmentsof the pad 20 are advanced through the water bath 16 for achieving asaturation thereof, and through the established air stream for achievingan evaporation of the water from the pad.

The opposite ends of the axle 30 are received within and are supportedby convenient structure including a pair of spaced bearing supports 36.Each of the sup ports 36 includes a bearing housing 38 within whichthere is arranged convenient bearings, not shown. Each bearing housingis arranged in a coaxial relationship with the drum 22 with the supportstherefor being rigidly fixed to the housing thereby to provide a rigidsupport for the opposite ends of the axle 30 so that the drum 22 issupported for rotation.

It isto be understood that the drum 22 is continuously driven inrotation at selected rates so that successive segments of the pad 20cyclically are wetted and subjected to the stream of air thus to achievethe desired heat absorption by evaporation of the water, whereby thetemperature of the air of the stream is reduced. In order to achieve therequired driving of the drum, a variable-speed motor 40, of anyconvenient design, is fixedly secured to the housing 10 throughconvenient mountings, such as stud bolts 42, and coupled to the drumthrough a drive train including a V- belt 44. As illustrated, the V-belt44 is trained about and extends between a pair of sheaves 46 and 48coupled to the output shaft 49 of the motor 40, and to the axle 30respectively.

The motor 40, through the belt 44 and its associated sheaves 46 and 48,drives the drum 22 at variable rates of rotation as dictated by selectedcooling rates for the prevailing climatic and atmospheric conditions. Inpractice, a rate of approximately 4 revolutions per minute has beenfound practical under most conditions, however, the rate is varied as isrequired to achieve a desired cooling effect.

While the motor 40 is a variable-speed motor, it should readily beapparent that by varying the diameter of the sheaves 46 and 48, a speedreduction drive may readily be provided so that a constant speed motorcan be employed, where desired. The manner, in which the rate ofrotation imparted to the drum 22 is varied, is a matter of convenience,therefore, any suitable drive coupling may be employed in lieu of a beltdrive.

Water is introduced into the pan 18 of the water bath 16 through anyconvenient supply system. As illustrated, a valve-controlled inlet 50 iscoupled with a water input conduit 52, the output of which is controlledthrough a convenient valve associated float 54. The float is formed of abuoyant material and rides" at the upper surface of the water retainedwithin the pan and includes an extended arm coupled with a convenientvalve, not designated, for the inlet so that the inlet 50 may be openedand closed in response to changes established in the water level of thepan 16 as the water is extracted by the pad 20.

Therefore, it should be appreciated that as atmospheric air is drawnthrough the intake duct 12, it is introduced axially into the drum 22and radially discharged from the periphery of the pad 20 in awatersaturated state. As the air egresses from the drum and periphery ofthe pad 20, the temperature thereof is reduced through the resultingevaporation processes. However, the air in passing through the pad alsotends to acquire particles of moisture. Consequently, the air as it isintroduced into the housing 10 is damp and contains a substantialquantity of minute particles of water delivered thereto as the air ispassed through and from the water-saturated pad 20.

However, as a flow of air is established between the periphery of thepad 20 and the discharge duct 14, the moisture particles are removed bya substantially dry, water-absorbent cooler pad 54 seated in aconvenient bracket 55 and positioned in the path of the flow of airbeing delivered to the discharge duct. The removed particles ultimatelyare evaporated for thereby extracting additional heat from the stream.The pad is formed of any convenient material which is capable ofabsorbing moisture as the air is delivered therethrough. Such pads arecommercially available and therefore a detailed description is omittedin the interest of brevity. However, if desired, the pad 54 may beformed of a material similar to that employed in forming pad 20.

In order to impel the flow of air from the periphery of the pad 20,through the pad 54 and through the discharge duct 14, a relativelyhigh-speed blower 56 is provided upstream of the discharge duct 14. Thisblower is so arranged as to have its discharge arranged in coaxialalignment with the duct 14. While the blower 56 may be of any convenientdesign, as presently employed, the blower is a radial-discharge,drum-type blower. As the specific blower employed may be varied andsince such devices are commercially available, a detailed description ofthe blower is omitted. Generally, however, the blower 56 includes acylindrical drum 58 of an open-end configuration, having a multiplicityof radially extended, air-dispelling blades 60. The drum is supportedfor rotation about an axis of rotation by a laterally extended axle 62,the ends of which are seated for support within convenient bearinghousings 64.

The drum 58 is enclosed within a convenient blower housing having anintake 72 provided therefor. The intake 72 includes coaxially arrangedopenings 73 through which air is introduced. As the drum 58 is driven inrotation, air is introduced at opposite sides of the housing 70 throughthe intake duct 72, axially of the drum 58, and is discharged therefromin radial directions for thereby driving the air through the dischargeduct 14. In practice, the drum 58 is driven at a relatively high rate ofrotation whereby the flow of air is accelerated to establish arelatively high velocity stream of air as it is passed from pad 20through the pad 54.

It is to be understood that the drum 58 is driven at selected rates ofrotation compatible with the extraction of particles of moisture fromthe air as well as to establish the pressures required in delivering thestream of air to its point of utilization. As a practical matter, a rateof rotation of approximately 400 revolutions per minute has been foundto be quite adequate for the purposes of delivering air through thecooler.

In practice, a variable-speed motor 74, fixed to the housing by studs75, is coupled with the drum 58 through a pair of sheaves 76 and 78 andan interconnecting V-belt 80 in a manner quite similar to that in whichthe motor 40 is coupled with the sheave 48 for driving the drum 22. Itis to be understood that the drum 58 is driven by the motor 74 at a ratesufficient to establish a desired How of air between the pad 20 and thepad 54 and that this flow continuously is accelerated as it passes fromthe pad 20 through the pad 54 into the discharge duct 14 of the housing10.

While various access doors may be provided for the housing 10 andemployed in seating the pad 54 within the bracket 55, a convenientlyhinged access door 84 is presently employed for accommodating aninsertion of the pad 54 into the brackets 55. With referenceparticularly to FIG. 1, it will be noted that the access door 84 alsoincludes an additional door or flap 86 pivotally connected at its distaledge. With this arrangement, there is established an auxiliary opening88 communicating with the flow of air being delivered to the blower 56,so that ambient atmospheric air may be introduced through the pad 54 andinto the stream of air being delivered to the intake duct 72 of theblower 56. This arrangement accommodates greater versatility incontrolling the temperature and the level of liquid moisture present asthe air is delivered from the duct 14. Since the flap 86 is pivotallyconnected to the door 84, itis to be understood that it selectively maybe closed for thus closing the opening 88 against passage of atmosphericair.

OPERATION The operation of the described embodiment of the subjectinvention is believed to be clearly apparent and is briefly summarizedat this point. While the cooler embodying the principles of the presentinvention may be mounted'at any convenient location, as presentlyemployed, it is supported adjacent to a building to be cooled. It is tobe understood that the duct 14 is connected with a convenient conduit,not shown, which serves to deliver the cooled air from the dischargeduct 14 to selected points of utilization.

With the cooler mounted, by brackets 11 and connected with a convenientvoltage source suitable for energizing the motors 40 and 74 andconnected with a convenient supply of water, the cooler is prepared foroperation.

As the motor 40 through the belts 44 and sheaves 46 and 48 serves todrive the drum 22 in rotation, the pad 20 continuously is passed throughthe water bath 16 and saturated by the water contained within the pan18. Concurrently, with the driving of the drum 22, the drum 58 of theblower 56 is driven at a relatively high rate of rotation by the motor74 acting through the associated belt 82 trained about the sheaves 76and 78. As the drum 58 is driven, the blades 60 expel air radiallytherefrom causing a stream of air to be accelerated axially into thedrum through the openings 73 of the blowers intake duct 72.Consequently, a vacuum condition is established adjacent to theperiphery of the pad 20 so that atmospheric air is forced through thesystem intake duct 12 and expelled radially through the pad 20. As theair is taken axially into the duct 12 and is driven through the pad 20,evaporation of the water within the pad occurs. As the water isconverted to a vapor, heat is extracted from the air causing thetemperature thereof to be reduced.

Since vaporization is incomplete, the air inherently includes suspendedminute particles of moisture in liquid form as the flow of air egressesfrom the peripheral surface of the pad 20 towards the blower 56.

As the air containing the particles of moisture is conducted toward theintake duct 72, of the blower 56, it is passed through the relativelydry moisture-absorbent pad 54 which serves to extract the particles ofmoisture therefrom so as to accommodate the establishment of arelatively dry, evaporatively cooled stream of air as the stream of airis accelerated to the intake duct of the blower. The pad 54 tends toremain dry due to an induced evaporation of the trapped moisture. Thisevaporation serves to further cool the air.

When the flap 86 is lifted, ambient atmospheric air is introducedthrough the opening 88 and a mixture of cooled dry air and ambientatmospheric air is achieved for the sake of controlling temperature andmoisture content for the air as it is discharged from the systemdischarge duct 14.

Although the invention has been herein shown and described in what isconceived to be the most practical and preferred method and apparatus,it is recognized that departures may be made therefrom within the scopeof the invention.

1 claim:

1. An evaporative cooler comprising:

A. a substantially closed housing having means defining an atmosphericair intake duct and a cool air discharge duct disposed in a spaced,communicating relationship for continuously conducting a standing streamof air through said housing;

B. means adjacent to the air intake duct defining a water bath withinthe housing;

C. a cylindrical pad formed of a pervious, water-absorbent materialincluding an open end disposed adjacent to the air intake duct foraxially receiving said stream;

D. a drum concentrically supporting said cylindrical pad about theperiphery thereof including a concentrically related axle extending fromthe opposite ends thereof;

E. a pair of laterally spaced, vertically oriented supports secured tothe housing adjacent to the water bath and coupled with said axle forsupporting said drum above said water bath in a manner such that asegment of the cylindrical pad continuously is submerged therein;

F. a first variable-speed drive unit operatively associated with saiddrum for driving the drum at a selectively variable rate, whereby saidstream is directed radially through said pad and successive segments ofsaid pad are wetted and subjected to said stream of air at a selectivelyvariable rate for thus evaporatively cooling the air at a selectivelyvariable rate;

G. a high-speed blower operatively supported within said stream,adjacent to the cool air discharge duct, for accelerating said stream ofair as it is directed through said cylindrical pad and for dischargingthe stream of airfrom the discharge duct;

H. a second variable-speed drive unit operatively associated with saidhigh-speed blower for driving the blower at a selectively variable rate,whereby said stream is accelerated and subsequently discharged throughsaid discharge duct at a selectively variable rate;

. a substantially dry, planar pad formed of a pervidischarge from thecool air discharge duct, so that moisture particles introduced into thestream by said cylindrical pad as the stream is directed therethroughare absorbed by said substantially dry pad; and

. an auxiliary atmospheric air intake unit means associated with saiddischarge duct and ambient atmosphere for introducing atmospheric aironly through said planar pad into said cool air discharge duct andmixing with the air in said cool air discharge duct.

1. An evaporative cooler comprising: A. a substantially closed housinghaving means defining an atmospheric air intake duct and a cool airdischarge duct disposed in a spaced, communicating relationship forcontinuously conducting a standing stream of air through said housing;B. means adjacent to the air intake duct defining a water bath withinthe housing; C. a cylindrical pad formed of a pervious, water-absorbentmaterial including an open end disposed adjacent to the air intake ductfor axially receiving said stream; D. a drum concentrically supportingsaid cylindrical pad about the periphery thereof including aconcentrically related axle extending from the opposite ends thereof; E.a pair of laterally spAced, vertically oriented supports secured to thehousing adjacent to the water bath and coupled with said axle forsupporting said drum above said water bath in a manner such that asegment of the cylindrical pad continuously is submerged therein; F. afirst variable-speed drive unit operatively associated with said drumfor driving the drum at a selectively variable rate, whereby said streamis directed radially through said pad and successive segments of saidpad are wetted and subjected to said stream of air at a selectivelyvariable rate for thus evaporatively cooling the air at a selectivelyvariable rate; G. a high-speed blower operatively supported within saidstream, adjacent to the cool air discharge duct, for accelerating saidstream of air as it is directed through said cylindrical pad and fordischarging the stream of air from the discharge duct; H. a secondvariable-speed drive unit operatively associated with said high-speedblower for driving the blower at a selectively variable rate, wherebysaid stream is accelerated and subsequently discharged through saiddischarge duct at a selectively variable rate; I. a substantially dry,planar pad formed of a pervious, waterabsorbent material disposedbetween the high-speed blower and the periphery of the cylindrical padin a stream-interrupting disposition whereby the stream of evaporativelycooled air is caused to pass through the planar pad, prior to itsdischarge from the cool air discharge duct, so that moisture particlesintroduced into the stream by said cylindrical pad as the stream isdirected therethrough are absorbed by said substantially dry pad; and J.an auxiliary atmospheric air intake unit means associated with saiddischarge duct and ambient atmosphere for introducing atmospheric aironly through said planar pad into said cool air discharge duct andmixing with the air in said cool air discharge duct.